Check out Blue Planet! They have a deep sea episode More on reddit.com

BBC's "The Blue Planet" documentary. I think it's episode 2.

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So there are a lot of documentary and buzz videos about the deep sea. Just depends on how woo woo you wana go... If you want factual-style documentaries I like... BBC What's Hiding In The Deep Sea https://youtu.be/TDNrM0Nt1Q0 David Freakin Attenborough walks us through the Mariana trench https://youtu.be/53igmq2ntKg Creatures of Light https://youtu.be/pvnAnBCuaCE Vampire squid https://youtu.be/pI6A218YE-Q "Deep Blue", the camera shots of great whites going at this buoy give me the chills... https://youtu.be/JlpNooty0io Coelacanth cyptid fish https://youtu.be/4jl_txxYQEA Magnapinna squid https://youtu.be/cfJ2iUQP8J4 If you want more "cornspiracy" creep/buzz videos here's a couple... 5 Mysterious Ocean Sounds https://youtu.be/ZZ4g5NVWaVw Creepiest ocean cryptids https://youtu.be/7qP3Iqxd8Fo Bobbitt Worm https://youtu.be/K_7ByiYbCYM Top 10 mythological ocean creatures https://youtu.be/pMbSZk6tFkA I personally LOVE True Facts videos by Zefrank1 and he has done a bunch on sea critters. They are funny and not too long. Here's his video about my favorite of all sea critters: The Mantis Shrimp aka The Chuck Norris of The Sea... https://youtu.be/F5FEj9U-CJM True Facts About The Octopus https://youtu.be/st8-EY71K84 If you look at the recommended videos under any of these links I have shared you should find plenty of rabbit holes to go down... One more... not ocean related... but still cool aquatic creepiness. Gustav The Man Eating Croc https://youtu.be/YU8NUVRmSHA Edit: Oarfish are pretty weird... https://youtu.be/Baxnlt61jYc Edit 2: The Legend of "Old Hitler" and "The Harbormaster" monster hammerheads https://youtu.be/5d1ykADH27w Edit 3: "Underwater" is a fictional movie that is right up this post's alley. https://youtu.be/jCFWEzIVILc More on reddit.com

Because you haven't mentioned it specifically, I'll point you to "The Blue Planet", which is a BBC documentary made in 2001 and narrated by Sir David Attenborough. Like all BBC nature documentaries it's stunning and I recommend it completely. Other than that, there are lots of mini-series like the recent "Shark", also on BBC, but co-produced with Animal Planet. I've watched numerous times and enjoyed "Andrea: Queen of Mantas", which features Dr. Andrea Marshall and her work researching giant manta rays. Her enthusiasm is infectious and the images are wonderful. I guess there's also Planet Earth, again by the BBC, although this doesn't focus on the oceans specifically. More on reddit.com